Alopecia (hair loss) is a common condition that results from diverse causes. In particular, alopecia frequently occurs in cancer patients who are treated with chemotherapeutic drugs such as cyclophosphamide (CY) and/or irradiation. Such agents damage hair follicles which contain mitotically active hair-producing cells. Such damage may cause abnormally slow growth of the hair or may lead to frank loss. While various attempts have been made to protect against alopecia or abnormal rates of hair growth during such treatments, there remains a need for an agent that prevents damage to hair follicles in a safe and effective manner.
U.S. Pat. No. 5,200,553 (issued Apr. 6, 1993) describes a class of compounds referred to as carboxylic acid esters that promote antitumor or immune responses. These compounds are believed to be capable of penetrating the membranes of cells and undergoing hydrolytic cleavage intracellularly to result in butyric acid, which can induce cell differentiation and displays antineoplastic activity.
The same class of compounds has also been shown to increase fetal hemoglobin levels in red blood cells and thus are useful for the treatment of .beta.-globin disorders such as sickle cell anemia and thalassemia (WO 95/24189, published Sep. 14, 1995). In addition, butyrate and .alpha.-amino-n-butyric acid have been used to stimulate the expression of fetal globin gene (Perrine et al., 1993, N. Eng. J. Med. 328:81; Perrine et al., 1989, Blood 74:454).
However, none of the aforementioned references discloses other activities of butyric acid or butyric acid derivatives, and in particular, the ability to protect against hair damage or loss in a mammal as described herein.